Elastomeric material extruders are widely used for forming shapes, profiles, tubes, treadstock, or the like. The feed stock is usually fed in strip form to a feed box which may be in part formed by a feed roll. From the feed box the strip is fed to the feed section of the screw to pass through the extruder and exit the die. Because of the presence of cured fines or foreign objects, or feed stock getting into bearings or other areas in the feed box, or compound changes, the feed box must be opened periodically for cleaning or servicing. This might usually entail shutting down the process, removal of the feed roll, cleaning the roll and box, and then replacement, perhaps readjustment, and restarting the process. The more quickly and readily this can be accomplished the better.
Also, if the feed box were designed to prevent feed stock intrusion into areas where it should not be, fewer clean outs would be required. Also, if the feed box contains readily adjustable roll seals, less intrusion, wear replacement and roll adjustment would be required. Moreover, the construction of the feed roll and box should enable size changes without removing the entire feed section or requiring realignment of the extruder.
Uniform feed is also an important consideration in that the lack thereof may not only result in such feed stock intrusion, but also create the possibility of starving, regurgitation or feed strip breakage, thus affecting the uniformity of the process and requiring more operator attention, downtime and maintenance. Where power driven feed rolls are employed, or other devices used to try to control uniformity of feed, the feed box or extruder may contain one or more sensors. However, such sensors oftentimes create a point of malfunction, or if of the tactile type, can be damaged or even swallowed by the extruder. Accordingly an extruder feed box which can provide uniform feed without sensors is desirable.